WATCH: Gov. Greg Abbott, Lupe Valdez Face Off In First And Only Debate

Left: Texas Gov. Greg Abbott speaks at an event where he announced his bid for re-election on July 14, 2017, in San Antonio. | Right: Texas gubernatorial candidate Lupe Valdez speaks at the Texas Democratic Convention on June 22, 2018, in Fort Worth.

Texas Tribune reporter Patrick Svitek points out that the debate will provide the widest audience yet for Valdez, "whose underdog challenge to Abbott has unfolded in the shadow of the blockbuster U.S. Senate race" that features Republican Sen. Ted Cruz and U.S. Rep. Beto O'Rourke, a Democrat.

As the Associated Press reports, from the start, Abbott has been in a stronger position than Valdez. His campaign has a bigger financial edge, and Valdez, the former Dallas County sheriff, has struggled to galvanize Democrats.

Valdez has said that as governor, she’d draw on her experience in law enforcement to bring people together around criminal justice reform and other issues facing Texas.

Facts to know before the debate

• Abbott and Valdez will get 60 seconds to answer questions and 30 seconds for each rebuttal. View more debate rules here.• Valdez would become Texas' first Hispanic and openly gay governor if elected.• Republicans haven't lost a statewide election in Texas in more than 20 years.

Guns, the Second Amendment, school shootings and this month's shooting death of Botham Jean were all testy topics for Ted Cruz and Beto O'Rourke during Friday night's U.S. Senate debate at Southern Methodist University in Dallas.

The Sunday debate between Republican U.S. Sen. Ted Cruz and U.S. Rep. Beto O’Rourke, D-El Paso, has been postponed due to weekend U.S. Supreme Court confirmation votes on the nomination of Judge Brett Kavanaugh.